@febkosq8/local-save/dist/index.d.ts

Lightweight wrapper around IndexedDB for secure and structured client-side data storage.

declare class LocalSave {
    dbName: DBName;
    encryptionKey?: EncryptionKey;
    categories: Category[];
    expiryThreshold: number;
    clearOnDecryptError: boolean;
    printLogs: boolean;
    constructor(config?: Config);
    /**
     * Opens a connection to the IndexedDB database.
     * It handles the database versioning and ensures that the required object stores are created if they do not exist.
     *
     * @internal
     *
     * @param version - The version of the database to open. Optional.
     *
     * @returns A promise that resolves to the opened 'IDBDatabase' instance.
     */
    private openDB;
    /**
     * Retrieves an object store from the IndexedDB database.
     * It handles the transaction mode and ensures that the requested object store is returned.
     *
     * If the object store does not exist in the database and the category is valid, it will create a new version of the database with the object store.
     *
     * @internal
     *
     * @param category - The name of the object store to retrieve.
     * @param mode - The mode for the transaction (default is "readonly").
     *
     * @returns A promise that resolves to the requested object store.
     *
     * @throws {LocalSaveError} Will throw an error if the object store does not exist in the database and the category is invalid
     */
    private getStore;
    /**
     * Retrieves the encryption key as a CryptoKey object.
     *
     * @internal
     * @returns A promise that resolves to a CryptoKey object.
     *
     * @throws {LocalSaveEncryptionKeyError} If the encryption key is not configured.
     * @throws {LocalSaveEncryptionKeyError} If the encryption key length is not 16, 24, or 32 characters.
     */
    private getEncryptKey;
    /**
     * Encrypts the provided data using AES-GCM encryption with the help of SubtleCrypto API.
     * Refer to https://developer.mozilla.org/en-US/docs/Web/API/SubtleCrypto/encrypt for more technical details.
     *
     * Generates a random 12-byte IV for each encryption.
     * Base64 encodes the IV and the encrypted data and returns the result as a string.
     *
     * If no encryption key is configured, it returns the data as is.
     *
     * @internal
     *
     * @param data The data to be encrypted. Should be an instance of DBItem.
     *
     * @returns A promise that resolves to the encrypted data as a base64 encoded string.
     *
     * @throws {LocalSaveEncryptionKeyError} If the encryption key is not configured.
     * @throws {LocalSaveError} If the encryption process fails.
     */
    private encryptData;
    /**
     * Decrypts the provided data using the configured encryption key.
     * If no encryption key is configured, it returns the data as is.
     *
     * @param encryptedBase64Data The data to decrypt, as a string.
     *
     * @returns The decrypted data as an object.
     *
     * @throws {LocalSaveEncryptionKeyError} If the encryption key is not configured.
     * @throws {LocalSaveError} If the decryption process fails.
     */
    decryptData(encryptedBase64Data: string): Promise<DBItem>;
    /**
     * Stores data in the specified category with the given item key.
     * If encryption key is configured, the data is encrypted first before being stored.
     *
     * @param category The category under which the data should be stored.
     * @param itemKey The key to identify the stored data.
     * @param data The data to be stored.
     *
     * @returns A promise that resolves to `true` if the operation was successful.
     *
     * @throws {LocalSaveError} Will reject the promise if an error occurs during the saving process.
     */
    set(category: Category, itemKey: string, data: unknown): Promise<true>;
    /**
     * Retrieves an item from the specified category in the IndexedDB.
     * If the item is not found, the promise resolves to 'null'.
     * If an encryption key is configured, the data is decrypted before being returned.
     *
     * @param category The category from which to retrieve the item.
     * @param itemKey The key of the item to retrieve.
     *
     * @returns A promise that resolves to the retrieved item or null if not found.
     *
     * @throws {LocalSaveError} Will reject the promise if an error occurs while decrypting the data. Depending on the 'clearOnDecryptError' configuration, all data for the category can be cleared.
     * @throws {LocalSaveError} Will reject the promise if an error occurs during the retrieval process.
     */
    get(category: Category, itemKey: string): Promise<DBItem | null>;
    /**
     * Removes an entry from the specified category and the specific itemKey in the IndexedDB store.
     *
     * @param category The category from which the item should be removed.
     * @param itemKey The key of the item to be removed.
     *
     * @returns A promise that resolves to `true` if the operation was successful.
     *
     * @throws {LocalSaveError} Will reject the promise if an error occurs during the removal process.
     */
    remove(category: Category, itemKey: string): Promise<true>;
    /**
     * Clears all entries in the specified category.
     *
     * @param category - The category to clear.
     *
     * @returns A promise that resolves to `true` if the operation was successful.
     *
     * @throws {LocalSaveError} Will reject the promise if an error occurs during the clearing process.
     */
    clear(category: Category): Promise<true>;
    /**
     * Expires data older than the specified number of days.
     *
     * This method iterates through all categories and removes items that have a timestamp
     * older than the specified number of days from the current date.
     *
     * @param {number} [days=this.expiryThreshold] The number of days to use as the threshold for expiring data.
     * Defaults to expiryThreshold from config if not provided.
     *
     * @returns A promise that resolves to `true` if the operation was successful.
     *
     * @throws {LocalSaveError} - Throws an error if there is an issue accessing the store or removing items.
     */
    expire(days?: number): Promise<true>;
    /**
     * Asynchronously destroys the database by deleting it from IndexedDB.
     *
     * @returns A promise that resolves to `true` if the operation was successful.
     *
     * @throws {LocalSaveError} Will reject the promise if an error occurs during the deletion process.
     */
    destroy(): Promise<true>;
}
type DBName = string;
type EncryptionKey = string;
type Category = string;
interface DBItem {
    timestamp: number;
    data: unknown;
}
type DBItemEncryptedBase64 = string;
interface Config {
    /**
     * The name of the database to use for local save
     *
     * @default "LocalSave"
     */
    dbName?: DBName;
    /**
     * The key to use for encrypting and decrypting data
     * Not providing this will store data in plain text
     * Should be a string without spaces of length 16, 24, or 32 characters
     *
     * @default undefined
     */
    encryptionKey?: EncryptionKey;
    /**
     * The categories to use for storing data
     * You can use these to separate different types of data
     * No spaces are allowed in the key
     *
     * @default ["userData"]
     */
    categories?: Category[];
    /**
     * The number of days to use as the threshold for expiring data
     *
     * @default '30' days
     */
    expiryThreshold?: number;
    /**
     * Whether to clear all data for a category if an error occurs while decrypting data
     * Most likely reason of error is due to an incorrect encryption key
     *
     * @default true
     */
    clearOnDecryptError?: boolean;
    /**
     * Whether to print logs
     * Includes debug and errors logs
     *
     * @default false
     */
    printLogs?: boolean;
}

export { type Category, type Config, type DBItem, type DBItemEncryptedBase64, type DBName, type EncryptionKey, LocalSave as default };